From a1f5ac6997269576f93a043fefdabf57d83e84ae Mon Sep 17 00:00:00 2001
From: Gary Guo <gary@garyguo.net>
Date: Sun, 24 Sep 2023 04:58:50 +0100
Subject: [PATCH 1/2] Remove drop-track-field-assign[-nonsend] test
These tests are identical to the ones without drop-track prefix, so
remove.
---
.../drop-track-field-assign-nonsend.rs | 44 -------------------
.../drop-track-field-assign-nonsend.stderr | 23 ----------
.../ui/async-await/drop-track-field-assign.rs | 43 ------------------
3 files changed, 110 deletions(-)
delete mode 100644 tests/ui/async-await/drop-track-field-assign-nonsend.rs
delete mode 100644 tests/ui/async-await/drop-track-field-assign-nonsend.stderr
delete mode 100644 tests/ui/async-await/drop-track-field-assign.rs
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.rs b/tests/ui/async-await/drop-track-field-assign-nonsend.rs
deleted file mode 100644
index 7002836ee47ff..0000000000000
--- a/tests/ui/async-await/drop-track-field-assign-nonsend.rs
+++ /dev/null
@@ -1,44 +0,0 @@
-// Derived from an ICE found in tokio-xmpp during a crater run.
-//@ edition:2021
-
-#![allow(dead_code)]
-
-#[derive(Clone)]
-struct InfoResult {
- node: Option<std::rc::Rc<String>>
-}
-
-struct Agent {
- info_result: InfoResult
-}
-
-impl Agent {
- async fn handle(&mut self) {
- let mut info = self.info_result.clone();
- info.node = None;
- let element = parse_info(info);
- let _ = send_element(element).await;
- }
-}
-
-struct Element {
-}
-
-async fn send_element(_: Element) {}
-
-fn parse(_: &[u8]) -> Result<(), ()> {
- Ok(())
-}
-
-fn parse_info(_: InfoResult) -> Element {
- Element { }
-}
-
-fn assert_send<T: Send>(_: T) {}
-
-fn main() {
- let agent = Agent { info_result: InfoResult { node: None } };
- // FIXME: It would be nice for this to work. See #94067.
- assert_send(agent.handle());
- //~^ cannot be sent between threads safely
-}
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.stderr b/tests/ui/async-await/drop-track-field-assign-nonsend.stderr
deleted file mode 100644
index 9fce4d61b3b6f..0000000000000
--- a/tests/ui/async-await/drop-track-field-assign-nonsend.stderr
+++ /dev/null
@@ -1,23 +0,0 @@
-error: future cannot be sent between threads safely
- --> $DIR/drop-track-field-assign-nonsend.rs:42:17
- |
-LL | assert_send(agent.handle());
- | ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
- |
- = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
-note: future is not `Send` as this value is used across an await
- --> $DIR/drop-track-field-assign-nonsend.rs:20:39
- |
-LL | let mut info = self.info_result.clone();
- | -------- has type `InfoResult` which is not `Send`
-...
-LL | let _ = send_element(element).await;
- | ^^^^^ await occurs here, with `mut info` maybe used later
-note: required by a bound in `assert_send`
- --> $DIR/drop-track-field-assign-nonsend.rs:37:19
- |
-LL | fn assert_send<T: Send>(_: T) {}
- | ^^^^ required by this bound in `assert_send`
-
-error: aborting due to 1 previous error
-
diff --git a/tests/ui/async-await/drop-track-field-assign.rs b/tests/ui/async-await/drop-track-field-assign.rs
deleted file mode 100644
index 491f80d062bbb..0000000000000
--- a/tests/ui/async-await/drop-track-field-assign.rs
+++ /dev/null
@@ -1,43 +0,0 @@
-// Derived from an ICE found in tokio-xmpp during a crater run.
-//@ edition:2021
-//@ build-pass
-
-#![allow(dead_code)]
-
-#[derive(Clone)]
-struct InfoResult {
- node: Option<String>
-}
-
-struct Agent {
- info_result: InfoResult
-}
-
-impl Agent {
- async fn handle(&mut self) {
- let mut info = self.info_result.clone();
- info.node = Some("bar".into());
- let element = parse_info(info);
- send_element(element).await;
- }
-}
-
-struct Element {
-}
-
-async fn send_element(_: Element) {}
-
-fn parse(_: &[u8]) -> Result<(), ()> {
- Ok(())
-}
-
-fn parse_info(_: InfoResult) -> Element {
- Element { }
-}
-
-fn main() {
- let mut agent = Agent {
- info_result: InfoResult { node: None }
- };
- let _ = agent.handle();
-}
From 197ad7537f24ff3441d6866d4f25b837e4708572 Mon Sep 17 00:00:00 2001
From: Gary Guo <gary@garyguo.net>
Date: Sun, 4 Jun 2023 16:50:59 +0100
Subject: [PATCH 2/2] Stop considering moved-out locals when computing auto
traits for generators
---
compiler/rustc_mir_transform/src/coroutine.rs | 44 ++++++++++++++++---
.../async-await/field-assign-nonsend.stderr | 11 ++---
tests/ui/async-await/temp-borrow-nonsend.rs | 23 ++++++++++
3 files changed, 66 insertions(+), 12 deletions(-)
create mode 100644 tests/ui/async-await/temp-borrow-nonsend.rs
diff --git a/compiler/rustc_mir_transform/src/coroutine.rs b/compiler/rustc_mir_transform/src/coroutine.rs
index 04d96f117072f..3ebc90632ee1d 100644
--- a/compiler/rustc_mir_transform/src/coroutine.rs
+++ b/compiler/rustc_mir_transform/src/coroutine.rs
@@ -69,10 +69,11 @@ use rustc_middle::ty::{
};
use rustc_middle::{bug, span_bug};
use rustc_mir_dataflow::impls::{
- MaybeBorrowedLocals, MaybeLiveLocals, MaybeRequiresStorage, MaybeStorageLive,
- always_storage_live_locals,
+ MaybeBorrowedLocals, MaybeInitializedPlaces, MaybeLiveLocals, MaybeRequiresStorage,
+ MaybeStorageLive, always_storage_live_locals,
};
-use rustc_mir_dataflow::{Analysis, Results, ResultsVisitor};
+use rustc_mir_dataflow::move_paths::MoveData;
+use rustc_mir_dataflow::{self, Analysis, MaybeReachable, Results, ResultsVisitor};
use rustc_span::def_id::{DefId, LocalDefId};
use rustc_span::{Span, sym};
use rustc_target::spec::PanicStrategy;
@@ -633,6 +634,12 @@ struct LivenessInfo {
/// Which locals are live across any suspension point.
saved_locals: CoroutineSavedLocals,
+ /// Which locals are live *and* initialized across any suspension point.
+ ///
+ /// A local that is live but is not initialized (i.e. it has been moved out of) does
+ /// not need to be accounted for in auto trait checking.
+ init_locals: DenseBitSet<Local>,
+
/// The set of saved locals live at each suspension point.
live_locals_at_suspension_points: Vec<DenseBitSet<CoroutineSavedLocal>>,
@@ -686,10 +693,18 @@ fn locals_live_across_suspend_points<'tcx>(
let mut liveness =
MaybeLiveLocals.iterate_to_fixpoint(tcx, body, Some("coroutine")).into_results_cursor(body);
+ let move_data = MoveData::gather_moves(body, tcx, |_| true);
+
+ // Calculate the set of locals which are initialized
+ let mut inits = MaybeInitializedPlaces::new(tcx, body, &move_data)
+ .iterate_to_fixpoint(tcx, body, Some("coroutine"))
+ .into_results_cursor(body);
+
let mut storage_liveness_map = IndexVec::from_elem(None, &body.basic_blocks);
let mut live_locals_at_suspension_points = Vec::new();
let mut source_info_at_suspension_points = Vec::new();
let mut live_locals_at_any_suspension_point = DenseBitSet::new_empty(body.local_decls.len());
+ let mut init_locals_at_any_suspension_point = DenseBitSet::new_empty(body.local_decls.len());
for (block, data) in body.basic_blocks.iter_enumerated() {
if let TerminatorKind::Yield { .. } = data.terminator().kind {
@@ -727,12 +742,26 @@ fn locals_live_across_suspend_points<'tcx>(
// The coroutine argument is ignored.
live_locals.remove(SELF_ARG);
- debug!("loc = {:?}, live_locals = {:?}", loc, live_locals);
+ inits.seek_to_block_end(block);
+ let mut init_locals: DenseBitSet<_> = DenseBitSet::new_empty(body.local_decls.len());
+ if let MaybeReachable::Reachable(bitset) = inits.get() {
+ for move_path_index in bitset.iter() {
+ if let Some(local) = move_data.move_paths[move_path_index].place.as_local() {
+ init_locals.insert(local);
+ }
+ }
+ }
+ init_locals.intersect(&live_locals);
+
+ debug!(
+ "loc = {:?}, live_locals = {:?}, init_locals = {:?}",
+ loc, live_locals, init_locals
+ );
// Add the locals live at this suspension point to the set of locals which live across
// any suspension points
live_locals_at_any_suspension_point.union(&live_locals);
-
+ init_locals_at_any_suspension_point.union(&init_locals);
live_locals_at_suspension_points.push(live_locals);
source_info_at_suspension_points.push(data.terminator().source_info);
}
@@ -757,6 +786,7 @@ fn locals_live_across_suspend_points<'tcx>(
LivenessInfo {
saved_locals,
+ init_locals: init_locals_at_any_suspension_point,
live_locals_at_suspension_points,
source_info_at_suspension_points,
storage_conflicts,
@@ -929,6 +959,7 @@ fn compute_layout<'tcx>(
) {
let LivenessInfo {
saved_locals,
+ init_locals,
live_locals_at_suspension_points,
source_info_at_suspension_points,
storage_conflicts,
@@ -950,6 +981,9 @@ fn compute_layout<'tcx>(
// this code runs on pre-cleanup MIR, and `ignore_for_traits = false` is the safer
// default.
let ignore_for_traits = match decl.local_info {
+ // If only the storage is required to be live, but local is not initialized,
+ // then we can ignore such type for auto trait purposes.
+ _ if !init_locals.contains(local) => true,
// Do not include raw pointers created from accessing `static` items, as those could
// well be re-created by another access to the same static.
ClearCrossCrate::Set(box LocalInfo::StaticRef { is_thread_local, .. }) => {
diff --git a/tests/ui/async-await/field-assign-nonsend.stderr b/tests/ui/async-await/field-assign-nonsend.stderr
index 418a0829c657e..9fec60618b8e2 100644
--- a/tests/ui/async-await/field-assign-nonsend.stderr
+++ b/tests/ui/async-await/field-assign-nonsend.stderr
@@ -5,14 +5,11 @@ LL | assert_send(agent.handle());
| ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
|
= help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
-note: future is not `Send` as this value is used across an await
- --> $DIR/field-assign-nonsend.rs:20:39
+note: captured value is not `Send` because `&mut` references cannot be sent unless their referent is `Send`
+ --> $DIR/field-assign-nonsend.rs:16:21
|
-LL | let mut info = self.info_result.clone();
- | -------- has type `InfoResult` which is not `Send`
-...
-LL | let _ = send_element(element).await;
- | ^^^^^ await occurs here, with `mut info` maybe used later
+LL | async fn handle(&mut self) {
+ | ^^^^^^^^^ has type `&mut Agent` which is not `Send`, because `Agent` is not `Send`
note: required by a bound in `assert_send`
--> $DIR/field-assign-nonsend.rs:37:19
|
diff --git a/tests/ui/async-await/temp-borrow-nonsend.rs b/tests/ui/async-await/temp-borrow-nonsend.rs
new file mode 100644
index 0000000000000..d5f573347fcec
--- /dev/null
+++ b/tests/ui/async-await/temp-borrow-nonsend.rs
@@ -0,0 +1,23 @@
+//@ check-pass
+//@ edition:2021
+
+use core::marker::PhantomData;
+
+struct B(PhantomData<*const ()>);
+
+fn do_sth(_: &B) {}
+
+async fn foo() {}
+
+async fn test() {
+ let b = B(PhantomData);
+ do_sth(&b);
+ drop(b);
+ foo().await;
+}
+
+fn assert_send<T: Send>(_: T) {}
+
+fn main() {
+ assert_send(test());
+}